The invention relates to a filling device for a motor vehicle fuel tank having at least one anti-surge tower with a delivery unit.
Fuel tanks are filled with fuel via filling nozzles. While this happens, if there is a sufficiently large amount of fuel, part of the fuel passes into the anti-surge tower. In order to ensure continuos filling of the anti-surge tower, a valve is frequently also arranged in the bottom region of the anti-surge tower. This valve ensures that the filling level of the fuel in the anti-surge tower corresponds at least to the height of that region of the fuel tank which surrounds the anti-surge tower. The delivery unit delivers fuel from the anti-surge tower to an internal combustion engine of the motor vehicle. When the level in the fuel tank is sufficiently high, during operation of the internal combustion engine fuel passes into the anti-surge tower via a sucking jet pump driven by the delivery unit. By this means, as fuel consumption progresses, the fuel tank which surrounds the anti-surge tower is emptied first of all, and finally the anti-surge tower itself is emptied.
A disadvantage of the known filling device is that after the fuel tank is completely emptied or when it is initially filled, a very large amount of fuel has to be poured into the fuel tank so that an amount of fuel which is sufficient for operating the delivery unit flows into the anti-surge tower. In the case of an emergency filling using a jerrycan which only holds a few liters, there is also the problem, when the motor vehicle is on a slope, of all of the fuel flowing into a side region of the fuel tank and therefore of no fuel at all passing into the anti-surge tower. The motor vehicle is then unable to be started.
It could be conceivable to conduct fuel which flows into the fuel tank through the filling nozzle directly into the anti-surge tower, so that the latter is filled first of all and then the overflowing fuel is distributed in the fuel tank. However, during normal filling using a fuel-pump nozzle, up to 60 liters of fuel per minute are supplied to the fuel tank, with the result that this design leads to the fuel foaming up. It has furthermore turned out that particularly at large volume flows, the greater part of the fuel sprays out of the anti-surge tower again.